GENERATION OF ANIMALS, II. i.-ii. 



of generating another creature like itself, since this 

 is a function which belongs to every animal and plant 

 that is perfect in its nature)." The reason why this 

 must of necessity be so is that once a thing has been 

 formed, it must of necessity grow. And though it 

 was generated by another thing bearing the same 

 name ^ {e.g., a man is generated by a man), it grows 

 by means of itself. So then, since it makes itself 

 grow, it is something '^ : and if indeed it is some one 

 thing, and if it is this first of all, then this must of 

 necessity be formed first. Thus, if the heart is 

 formed first in certain animals (or the part analogous 

 to the heart, in those animals which have no heart), 

 we may suppose that it is the heart (or its analogue) 

 which supplies the principle.'' 



The queries raised earher have now been dealt 

 with. We have answered the question. What is the 

 cause (in the sense of principle) of the generation of 

 each individual — what is that which first sets it in 

 movement and fashions it ? 



A puzzle which may now be propounded is, WTiat II 

 is the nature of Semen r Semen when it leaves the Semen, 

 animal is thick and white, but when it cools it becomes 

 fluid Uke water and is of the colour of water. This 



nutritive Soul, viz., the heart- And that is why the heart is 

 the first thing to be formed." Cf. 740 a 21 (where there is no 

 need to alter the text). 



'' The meaning of this passage seems to be that the semen, 

 though it must have (and be) Soul, can have (and be) Soul 

 potentially only ; and the realizing of this potentiality, 

 which is the process of formation or generation (of which the 

 parent is the agent), goes on gradually — thus, the first part 

 of the Soul to be formed, generated, or realized, is the part 

 which produces growth (to dpeTrriKov), and with it the part of 

 the body in which that part of the Soul resides, viz., the 

 heart. (See 763 b 25, n.) 



157 



